Semiconductor device

ABSTRACT

Disclosed is a semiconductor device having a wafer level package structure which is characterized by containing a resin layer composed of a resin composition which is curable at 250° C. or less. Such a semiconductor device having a wafer level package structure is excellent in low stress properties, solvent resistance, low water absorbency, electrical insulation properties, adhesiveness and the like.

TECHNICAL FIELD

The present invention relates to a semiconductor device having a waferlevel package structure.

BACKGROUND ART

Polyimide resins and polybenzoxazole resins having excellent heatresistance, electrical characteristics and mechanical characteristics orthe like have been used for surface protection films and interlayerinsulating films of a semiconductor element (Patent Document 1).

However, when a polyimide resin has been used, there exists a problem inthat a polyamide acid, which is a precursor before curing, has causedthe copper used for wiring to corrode, and as a result, migration hasoccurred. Also, the polyimide resin has a high cure temperature of about350° C., and therefore there is a problem that the copper has beenoxidized in the cure reaction.

Furthermore, the high integration and multilayering of a semiconductorelement which is represented by the semiconductor device having a waferlevel package structure has caused large problems such as the delay ofsignals in the wiring and the increase of power consumption. Since thepolyimide resin has a comparatively high dielectric constant of 2.6 to3.5, materials having a low dielectric constant have been required forthe surface protection films and the interlayer insulating films.

In addition, there exists a problem in that both the polyimide resin andthe polybenzoxazole resin have had large stress. When these resin layershave been used in the frontier semiconductor, a problem exists in thatthe semiconductor element has been broken because of the stress of theprotective film itself, and the stress from the outside has not beenable to be reduced. Thereby, lower stress properties have been requiredfor the protective film.

The resin composition used for the semiconductor device having the waferlevel package structure for solving the above problems has not beenknown until now.

Patent Document 1: Japanese Patent Laid-Open No. 2001-194796 DISCLOSUREOF THE PRESENT INVENTION Problems to be Solved

It is an object of the present invention to provide a semiconductordevice having a wafer level package structure which is excellent in lowstress properties, solvent resistance, low water absorbency, electricinsulation properties and adhesiveness or the like.

Measures for Solving the Problems

As the result of extensive investigations to solve the above-mentionedproblems, the present inventors have completed the present invention.

That is, according to an aspect of the present invention, there isprovided a semiconductor device having a wafer level package structurecomprising a resin layer composed of a resin composition which iscurable at 250° C. or less.

According to another aspect of the present invention, there is provideda semiconductor device having a wafer level package structure comprisinga resin layer having an elastic modulus after curing of 0.1 GPa or morebut no more than 2.0 GPa.

According to another aspect of the present invention, there is provideda semiconductor device having a wafer level package structure comprisinga resin layer having a dielectric constant of 2.6 or less.

According to another aspect of the present invention, there is alsoprovided a semiconductor device having a wafer level package structurecomprising a resin layer composed of a resin composition which iscurable at 250° C. or less, the resin composition having an elasticmodulus after curing of 0.1 GPa or more but no more than 2.0 GPa andhaving a dielectric constant of 2.6 or less.

According to another aspect of the present invention, there is provideda semiconductor device having a wafer level package structure comprisinga resin layer composed of a resin composition containing a cyclic olefinresin (A) having an epoxy group and a photoacid generator (B).

In the semiconductor device of the present invention, the cyclic olefinresin is not particularly limited. However, in an embodiment of thepresent invention, the cyclic olefin resin may be a polynorborneneresin.

Furthermore, in an aspect of the present invention, the cyclic olefinresin (A) having an epoxy group may contain a repeating unit representedby the formula (1):

wherein X is O, CH₂ or (CH₂)₂; n is an integer of 0 to 5; R¹ to R⁴ areeach independently selected from a hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an aryl group, an aralkyl group, afunctional group containing an ester group, a functional groupcontaining a ketone group, a functional group containing an ether group,and a functional group containing an epoxy group; R¹ to R⁴ may bedifferent in a repetition of a monomer; and at least one of R¹ to R⁴ inall the repeating units is the functional group having an epoxy group.

In another aspect of the present invention, the cyclic olefin resin (A)having an epoxy group may contain repeating units represented by theformulae (2) and (3):

wherein R¹ to R⁷ are each independently selected from a hydrogen atom,an alkyl group, an alkenyl group, an alkynyl group, an aryl group, anaralkyl group, a functional group containing an ester group, afunctional group containing a ketone group, and a functional groupcontaining an ether group; and R¹ to R⁷ may be different in a repetitionof a monomer.

Furthermore, in another aspect of the present invention, the cyclicolefin resin (A) having an epoxy group may contain repeating unitsrepresented by the formulae (4), (5) and (6):

wherein n is an integer of 0 to 5; R¹ to R¹⁰ are each independentlyselected from a hydrogen atom, an alkyl group, an alkenyl group, analkynyl group, an aryl group, an aralkyl group, a functional groupcontaining an ester group, a functional group containing a ketone group,and a functional group containing an ether group; and R¹ to R¹⁰ may bedifferent in a repetition of a monomer.

Furthermore, in an aspect of the present invention, the cyclic olefinresin (A) having an epoxy group may contain a repeating unit representedby the formula (7):

wherein Y is O, CH₂ or (CH₂)₂; Z is —CH₂—CH₂— or —CH═CH—; l is aninteger of 0 to 5; R¹ to R⁴ are each independently selected from ahydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaryl group, an aralkyl group, a functional group containing an estergroup, a functional group containing a ketone group, a functional groupcontaining an ether group, and a functional group containing an epoxygroup; R¹ to R⁴ may be different in a repetition of a monomer; and atleast one of R¹ to R⁴ in all the repeating units has the epoxy group.

EFFECTS OF THE INVENTION

The present invention can provide a semiconductor device having aphotosensitive resin composition which is excellent in low stressproperties, solvent resistance, low water absorbency, electricinsulation properties and adhesiveness or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a pad portion of an example of asemiconductor device of the present invention;

FIGS. 2A to 2D are sectional views showing production steps of anexample of a semiconductor device of the present invention;

FIGS. 3A to 3C are sectional views showing production steps of anexample of a semiconductor device of the present invention; and

FIGS. 4A and 4B are sectional views showing production steps of anexample of a semiconductor device of the present invention.

DESCRIPTION OF SYMBOLS

-   1 silicon wafer-   2 Al pad-   3 passivation film-   4 buffer coat film-   5 metal (e.g. Cr or Ti) film-   6 wiring (e.g. Al or Cu)-   7 insulating film-   8 barrier metal-   9 resist-   10 solder-   11 flux-   12 solder bump

BEST MODE FOR CARRYING OUT THE INVENTION

General examples of cyclic olefin monomers used in the present inventioninclude monocyclic compounds such as cyclohexene and cyclooctene, andpolycyclic compounds such as norbornene, norbornadiene,dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene,tricyclopentadiene, dihydrotricyclopentadiene, tetracyclopentadiene anddihydrotetracyclopentadiene. Substituted compounds prepared by bondingfunctional groups to these monomers can be also used.

Examples of the cyclic olefin resins used in the present inventioninclude polymers of the above cyclic olefin monomers. As thepolymerization method, there are used known methods such as randompolymerization and block polymerization. Specific examples include(co)polymers of norbornene type monomers, copolymers of the norbornenetype monomers and other monomers capable of being copolymerized such asα-olefins, and hydrogen added compounds of these copolymers. Thesecyclic olefin resins can be produced by the known polymerizationmethods, and the examples of the polymerization methods include anaddition polymerization method and a ring-opening polymerization method.Of these, polymers prepared by addition-(co)polymerizing the norbornenemonomers are preferable. However, the present invention is not limitedthereto in any way.

Examples of the addition polymers of the cyclic olefin resin includepolynorbornene resins. Specific examples thereof include (1) addition(co)polymers of norbornene type monomers prepared byaddition-(co)polymerizing the norbornene type monomers, (2) additioncopolymers of the norbornene type monomers and ethylene or α-olefins,and (3) addition copolymers of the norbornene type monomer,nonconjugated diene and, as necessary, other monomers. These resins canbe prepared by all the known polymerization methods.

Examples of the ring-opening polymers of the cyclic olefin resin includepolynorbornene resins. Specific examples thereof include (4)ring-opening (co)polymers of the norbornene type monomer and resinsprepared by hydrogenating the (co)polymer as necessary; (5) ring-openingcopolymers of the norbornene type monomer and ethylene or α-olefins, andresins prepared by hydrogenating the (co)polymer as necessary; and (6)ring-opening copolymers of the norbornene type monomer and nonconjugateddiene or other monomers, and resins prepared by hydrogenating the(co)polymer as necessary. These resins can be prepared by all the knownpolymerization methods.

Of these, (1) the addition (co)polymers prepared byaddition-(co)polymerizing the norbornene type monomers are preferable.However, the present invention is not limited thereto in any way.

As the cyclic olefin monomer used for producing the cyclic olefin resinhaving an epoxy group used in the present invention, the norbornene typemonomer represented by the general formula (8) is preferable.

Specific examples of the alkyl groups include methyl, ethyl, propyl,isopropyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, desyl, dodecyl,cyclopentyl, cyclohexyl and cyclooctyl groups. Examples of the alkenylgroups include vinyl, allyl, butynyl and cyclohexyl groups. Examples ofthe alkynyl groups include ethynyl, 1-propynyl, 2-propynyl, 1-butynyland 2-butynyl groups. Examples of the aryl groups include phenyl,naphthyl and anthracenyl groups. Examples of the aralkyl groups includebenzyl and phenethyl groups. However, the present invention is notlimited thereto in any way.

Referring to the functional group containing the ester group, thefunctional group containing the ketone group and the functional groupcontaining the ether group, as long as the functional groups have thesegroups, the structure thereof is not particularly limited. Preferableexamples of the functional groups containing the epoxy group include afunctional group having a glycidyl ether group. However, as long as thefunctional group has the epoxy group, the structure thereof is notparticularly limited.

The cyclic olefin monomer used for producing the cyclic olefin resinused in the present invention is not particularly limited. However, forexample, there can be used a monomer represented by the formula (8):

wherein X is O, CH₂ or (CH₂)₂; n is an integer of 0 to 5; R¹ to R⁴ areeach independently selected from a hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an aryl group, an aralkyl group, afunctional group containing an ester group, a functional groupcontaining a ketone group, a functional group containing an ether group,and a functional group containing an epoxy group. Here, R¹ to R⁴ may bedifferent in each monomer to be used, and at least one of R¹ to R⁴ inall the monomers to be used is a functional group having an epoxy group.

Examples of the cyclic olefin monomers used for producing the cyclicolefin resin used in the present invention include5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-propyl-2-norbornene,5-butyl-2-norbornene, 5-pentyl-2-norbornene, 5-hexyl-2-norbornene,5-heptyl-2-norbornene, 5-octyl-2-norbornene, 5-nonyl-2-norbornene and5-decyl-2-norbornene as the monomer having an alkyl group;5-allyl-2-norbornene, 5-methylidene-2-norbornene,5-ethylidene-2-norbornene, 5-isopropylidene-2-norbornene,5-(2-propenyl)-2-norbornene, 5-(3-butenyl)-2-norbornene,5-(1-methyl-2-propenyl)-2-norbornene, 5-(4-pentenyl)-2-norbornene,5-(1-methyl-3-butenyl)-2-norbornene, 5-(5-hexenyl)-2-norbornene,5-(1-methyl-4-pentenyl)-2-norbornene,5-(2,3-dimethyl-3-butenyl)-2-norbornene,5-(2-ethyl-3-butenyl)-2-norbornene,5-(3,4-dimethyl-4-pentenyl)-2-norbornene, 5-(7-octenyl)-2-norbornene,5-(2-methyl-6-heptenyl)-2-norbornene,5-(1,2-dimethyl-5-hexenyl)-2-norbornene,5-(5-ethyl-5-hexenyl)-2-norbornene, and5-(1,2,3-trimethyl-4-pentenyl)-2-norbornene, 5-allyl-2-norbornene,5-methylidene-2-norbornene, 5-ethylidene-2-norbornene,5-isopropylidene-2-norbornene, 5-(2-propenyl)-2-norbornene,5-(3-butenyl)-2-norbornene, 5-(1-methyl-2-propenyl)-2-norbornene,5-(4-pentenyl)-2-norbornene, 5-(1-methyl-3-butenyl)-2-norbornene,5-(5-hexenyl)-2-norbornene, 5-(1-methyl-4-pentenyl)-2-norbornene,5-(2,3-dimethyl-3-butenyl)-2-norbornene,5-(2-ethyl-3-butenyl)-2-norbornene,5-(3,4-dimethyl-4-pentenyl)-2-norbornene, 5-(7-octenyl)-2-norbornene,5-(2-methyl-6-heptenyl)-2-norbornene,5-(1,2-dimethyl-5-hexenyl)-2-norbornene,5-(5-ethyl-5-hexenyl)-2-norbornene, and5-(1,2,3-trimethyl-4-pentenyl)-2-norbornene as the monomer having analkenyl group; 5-ethynyl-2-norbornene as the monomer having an alkynylgroup;1,1,3,3,5,5-hexamethyl-1,5-dimethylbis(2-(5-norbornene-2-yl)ethyl)trisiloxaneas the monomer having a silyl group; 5-phenyl-2-norbornene,5-naphthyl-2-norbornene, 5-pentafluorophenyl-2-norbornene as the monomerhaving an aryl group; 5-benzyl-2-norbornene, 5-phenethyl-2-norbornene,5-pentafluorophenylmethyl-2-norbornene,5-(2-pentafluorophenylethyl)-2-norbornene,5-(3-pentafluorophenylpropyl)-2-norbornene as the monomer having anaralkyl group; dimethylbis((5-norbornene-2-yl)methoxy)silane,5-trimethoxysilyl-2-norbornene, 5-triethoxysilyl-2-norbornene,5-(2-trimethoxysilylethyl)-2-norbornene,5-(2-triethoxysilylethyl)-2-norbornene,5-(3-trimethoxysilylpropyl)-2-norbornene,5-(4-trimethoxybutyl)-2-norbornene, and5-trimethylsilylmethylether-2-norbornene as the monomer having analkoxysilyl group; 5-norbornene-2-methanol and its alkyl ether,5-norbornene-2-methyl acetate, 5-norbornene-2-methyl propionate,5-norbornene-2-methyl butyrate, 5-norbornene-2-methyl valerate,5-norbornene-2-methyl caproate, 5-norbornene-2-methyl caprylate,5-norbornene-2-methyl caprate, 5-norbornene-2-methyl laurate,5-norbornene-2-methyl stearate, 5-norbornene-2-methyl oleate,5-norbornene-2-methyl linolenate, 5-norbornene-2-carboxylic acid, methyl5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, t-butyl5-norbornene-2-carboxylate, i-butyl 5-norbornene-2-carboxylate,trimethylsilyl 5-norbornene-2-carboxylate, triethylsilyl5-norbornene-2-carboxylate, isobornyl 5-norbornene-2-carboxylate,2-hydroxyethyl 5-norbornene-2-carboxylate, methyl5-norbornene-2-methyl-2-carboxylate, 5-norbornene-2-methyl cinnamate,5-norbornene-2-methyl ethyl carbonate, 5-norbornene-2-methyl n-butylcarbonate, 5-norbornene-2-methyl t-butyl carbonate,5-methoxy-2-norbornene, 5-norbornene-2-methyl (meth)acrylate,5-norbornene-2-ethyl (meth)acrylate, 5-norbornene-2-n-butyl(meth)acrylate, 5-norbornene-2-n-propyl (meth)acrylate,5-norbornene-2-i-butyl (meth)acrylate, 5-norbornene-2-i-propyl(meth)acrylate, 5-norbornene-2-hexyl (meth)acrylate,5-norbornene-2-octyl (meth)acrylate, and 5-norbornene-2-decyl(meth)acrylate as the monomer having a hydroxyl group, an ether group, acarboxyl group, an ester group, an acrylyl group or a methacryloylgroup; 5-[(2,3-epoxypropoxy)methyl]-2-norbornene as the monomer havingan epoxy group;8-methoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-ethoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-n-propylcarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-i-propylcarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-n-butoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-(2-methylpropoxy)carbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-(1-methylpropoxy)carbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-t-butoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-cyclohexyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-(4′-t-butylcyclohexyloxy)carbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-phenoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-tetrahydrofuranyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]-3-dodecene,8-tetrahydropyranyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-ethoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-n-propoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-i-propoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-n-butoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-(2-methylpropoxy)carbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-(1-methylpropoxy)carbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-t-butoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-cyclohexyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-(4′-t-butylcyclohexyloxy)carbonyrtetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-phenoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-tetrahydrofuranyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyl-8-tetrahydropyranyloxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]-3-dodecene,8-methyl-8-acetoxytetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(methoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(ethoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(n-propoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(i-propoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(n-butoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(t-butoxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(cyclohexyloxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(phenoxyloxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8,9-di(tetrahydrofuranyloxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]-3-dodecene,8,9-di(tetrahydropyranyloxycarbonyl)tetracyclo[4.4.0.1^(2,5).1^(7,10)]-3-dodecene,8,9-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene-8-carboxylic acid,8-methyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene-8-carboxylic acid,8-methyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-ethyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene,8-methyltetracyclo[4.4.0.1^(2,5).0^(1,6)]dodec-3-ene,8-ethylidenetetracyclo[4.4.0.1^(2,5).1^(7,10)]dodec-3-ene, and8-ethylidenetetracyclo[4.4.0.1^(2,5).1^(7,10)0^(1,6)]dodec-3-ene as themonomer containing a tetracyclo ring.

Preferably, the cyclic olefin resin (A) having an epoxy group used inthe present invention is an addition (co) polymer of a norbornene typemonomer represented by the general formula (9),

wherein X is O, CH₂ or (CH₂)₂; n is an integer of 0 to 5; m is aninteger of 10 to 10,000; R¹ to R⁴ are specifically selected from ahydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, anaryl group, an aralkyl group, a functional group containing an estergroup, a functional group containing a ketone group, a functional groupcontaining an ether group, and a functional group containing an epoxygroup; R¹ to R⁴ may be different in a repetition of a monomer; and atleast one of R¹ to R⁴ in all the repeating units is the functional grouphaving an epoxy group.

As the cyclic olefin resin (A) having an epoxy group used in the presentinvention, polymers represented by the formulae (10) and (11):

are preferable in view of the polymer characteristic after curing,wherein m and n are an integer of 1 or more; R¹ to R⁷ are eachindependently selected from a hydrogen atom, an alkyl group, an alkenylgroup, an alkynyl group, an aryl group, an aralkyl group, a functionalgroup containing an ester group, a functional group containing a ketonegroup, and a functional group containing an ether group; and R¹ to R⁷may be different in a repetition of a monomer,

wherein l, m and n are an integer of 1 or more; p is an integer of 0 to5; R¹ to R¹⁰ are each independently selected from a hydrogen atom, analkyl group, an alkenyl group, an alkynyl group, an aryl group, anaralkyl group, a functional group containing an ester group, afunctional group containing a ketone group, and a functional groupcontaining an ether group; and R¹ to R″ may be different in a repetitionof a monomer. As shown in the formula (11), the solubility to polarsolvents such as cyclopentanone and heptanone used as a solvent for anegative type developing solution can be enhanced by introducing thenorbornene monomer having an aralkyl group into the polymer, and theintroduction has such an advantage that the polymer has excellentoperability.

As the cyclic olefin resin (A) having an epoxy group used in the presentinvention, a polymer represented by the formula (12):

more desirable in view of the polymer characteristic after curing,wherein l, m and n are an integer of 1 or more. A film having lowelastic modulus is obtained by introducing a monomer having a desylgroup. Also, a film excellent in low water absorbency, chemicalresistance and polar solvent solubility is obtained by introducing amonomer having a phenylethyl group.

The content of the monomer having an epoxy group in the copolymer can bedetermined based on whether the copolymer is crosslinked by exposure anda crosslink density capable of enduring the developing solution isobtained. The monomer having an epoxy group can be used at a ratio of 5to 95 mol %, preferably 20 to 80 mol %, and more preferably 30 to 70% inthe polymer. The polymer thus obtained exhibits excellent physicalcharacteristics such as low water absorbency (<0.3 wt %), low dielectricconstant (<2.6), low dielectric loss (0.001), and glass transition point(170 to 400° C.).

Although the cyclic olefin resin (A) having an epoxy group used in thepresent invention can be generally prepared by directly polymerizingmonomers containing the epoxy group in a molecule, the same polymer canbe also prepared by a method for introducing an epoxy group into a sidechain by a modification reaction after the polymerization. Examples ofthe modification reactions include known methods such as a method forsubjecting a unsaturated monomer containing an epoxy group to graftreaction with the above polymer, a method for reacting a reactivefunctional moiety of the above polymer with a compound having an epoxygroup, and a method for directly epoxidizing the above polymer having acarbon-carbon double bond in a molecule using an epoxidizing agent suchas peracid and hydroperoxide.

The addition polymer of the cyclic olefin resin is prepared bycoordination polymerization or radical polymerization due to a metalcatalyst. Of these, in the coordination polymerization, a polymer isprepared by polymerizing monomers in a solution in the presence of atransition metal catalyst (NiCOLE R. GROVE et al. Journal of PolymerScience: part B, Polymer Physics, Vol. 37, 3003 to 3010 (1999)).

Typical nickel and platinum catalysts as the metal catalysts used forthe coordination polymerization are disclosed in PCT WO 97/33198 and PCTWO 00/20472. Examples of the metal catalysts for coordinationpolymerization include known metal catalysts such as(toluene)bis(perfluorophenyl)nickel,(methylene)bis(perfluorophenyl)nickel,(benzene)bis(perfluorophenyl)nickel,bis(tetrahydro)bis(perfluorophenyl)nickel,bis(ethylacetate)bis(perfluorophenyl)nickel, andbis(dioxane)bis(perfluorophenyl)nickel.

Radical polymerization techniques are disclosed in Encyclopedia ofPolymer Science, John Wiley & Sons, 13, 708 (1988).

In the radical polymerization, monomers are generally reacted in asolution by raising the temperature of the solution to 50° C. to 150° C.in the presence of a radical initiator. Examples of the radicalinitiators include azobis(isobutyronitrile) (AIBN), benzoyl peroxide,lauryl peroxide, azobiskaptro nitrile, azobis isolero nitrile andt-butyl hydrogen peroxide.

The ring-opening polymer of the cyclic olefin resin is prepared byring-opening (co)polymerizing at least one kind of norbornene typemonomer using titanium and tungsten compounds as a catalyst by knownring-opening polymerization methods to produce a ring-opening(co)polymer, by hydrogenating the carbon-carbon double bond in thering-opening (co)polymer by a usual hydrogenating method as necessary toproduce a thermoplastic saturated norbornene resin.

Suitable polymerization solvents for the above polymerization systeminclude hydrocarbon solvents and aromatic solvents. Examples of thehydrocarbon solvents include, but are not limited to, pentane, hexane,heptane and cyclohexane. Examples of the aromatic solvents, but are notlimited to, benzene, toluene, xylene and mesitylene. Diethyl ether,tetrahydrofuran, ethyl acetate, ester, lactone, ketone and amide can bealso used. These solvents may be used singly or in admixture as thepolymerization solvent.

The molecular weight of the cyclic olefin resin of the present inventioncan be controlled by changing a ratio of an initiator and monomer orchanging polymerization time. When the above metal catalyst forcoordination polymerization is used, the molecular weight can becontrolled by using a chain transfer catalyst as disclosed in U.S. Pat.No. 6,136,499. In the present invention, α-olefins such as ethylene,propylene, 1-hexane, 1-decene and 4-methyl-1-pentene are suitable forcontrolling the molecular weight.

In the present invention, the weight average molecular weight is 10,000to 500,000, preferably 30,000 to 100,000, and more preferably 50,000 to80,000. The weight average molecular weight can be measured by gelpermeation chromatography (GPC) using polynorbornene as a standard (inreference to ASTMDS3536-91).

All known compounds as a photoacid generator can be used. The photoacidgenerator crosslinks the epoxy group and increases adhesiveness to asubstrate according to the subsequent curing. Preferable examples of thephotoacid generators include onium salts, halogen compounds, sulfonatesand the mixture thereof. Examples of the onium salts include diazoniumsalts, ammonium salts, iodonium salts, sulfonium salts, phosphoniumsalts, arsonium salts and oxonium salts. As long as a compound canproduce counter anions with the above onium salts, the counter anionsare not limited. Examples of the counter anions include, but are notlimited to, boric acid, arsonium acid, phosphoric acid, antimonic acid,sulfonate, carboxylic acid and chloride thereof. As the photoacidgenerator of the onium salts, triphenylsulfonium tetrafluoroborate,triphenylsulfonium tetrafluoroborate, triphenylsulfoniumtetrafluoroarsenate, triphenylsulfonium tetrafluorophosphate,triphenylsulfonium pentafluorosulfate, 4-thiophenoxydiphenylsulfoniumtetrafluoroborate, 4-thiophenoxydiphenylsulfonium hexafluoroantimonate,4-thiophenoxydiphenylsulfonium hexafluoroarsenate,4-thiophenoxydiphenylsulfonium tetrafluorophosphate,4-thiophenoxydiphenylsulfonium trifluorosulfonate,4-t-butylphenyldiphenylsulfonium tetrafluoroborate,4-t-butylphenyldiphenylsulfonium hexafluoroarsenate,4-t-butylphenyldiphenylsulfonium hexafluoroantimonate,4-t-butylphenyldiphenylsulfonium hexafluorophosphonate,4-t-butylphenyldiphenylsulfonium trifluorosulfonate,tris(4-methylphenyl)sulfonium tetrafluoroborate,tris(4-methylphenyl)sulfonium tetrafluoroborate,tris(4-methylphenyl)sulfonium hexafluoroarsenate,tris(4-methylphenyl)sulfonium hexafluorophosphate,tris(4-methylphenyl)sulfonium hexafluorosulfonate,tris(4-methoxyphenyl)sulfonium tetrafluoroborate,tris(4-methylphenyl)sulfonium hexafluoroantimonate,tris(4-methylphenyl)sulfonium hexafluorophosphonate,tris(4-methylphenyl)sulfonium trifluorosulfonate, triphenyliodoniumtetrafluoroborate, triphenyliodonium hexafluoroantimonate,triphenyliodonium hexafluoroarsenate, triphenyliodoniumhexafluorophosphonate, triphenyliodonium trifluorosulfonate,3,3-dinitrodiphenyliodonium tetrafluoroborate,3,3-dinitrodiphenyliodonium hexafluoroantimonate,3,3-dinitrodiphenyliodonium hexafluoroarsenate,3,3-dinitrodiphenyliodonium trifluorosulfonate,4,4-dinitrodiphenyliodonium tetrafluoroborate,4,4-dinitrodiphenyliodonium hexafluoroantimonate,4,4-dinitrodiphenyliodonium hexafluoroarsenate, and4,4-dinitrodiphenyliodonium trifluorosulfonate may be used singly or inadmixture.

Examples of the photoacid generators containing halogen other thanfluoride include 2,4,6-tris(trichloromethyl)triazine,2-allyl-4,6-bis(trichloromethyl)triazine,α,β,α-tribromomethylphenylsulfone, α,α,2,3,5,6-hexachloroxylene,2,2-bis(3,5-dibromo-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoroxylene,1,1,1-tris(3,5-dibromo-4-hydroxyphenyl)ethane, and the mixture thereof.

Examples of sulfonate photoacid generators include, but are not limitedto, 2-nitrobenzyl tosylate, 2,6-dinitrobenzyl tosylate,2,4-dinitrobenzyl tosylate, 2-nitrobenzenemethyl sulfonate,2-nitrobenzyl acetate, 9,10-dimethoxy anthracene-2-sulfonate,1,2,3-tris(methane sulfonyloxy)benzene, 1,2,3-tris (ethanesulfonyloxy)benzene, and 1,2,3-tris(propane sulfonyloxy)benzene.

Preferable examples of the photoacid generators include4,4′-di-t-butylphenyl iodonium triflate,4,4′,4″-tris(t-butylphenyl)sulphonium triflate; diphenyliodoniumtetrakis(pentafluorophenyl)borate; triphenylsulfoniumdiphenyliodoniumtetrakis(pentafluorophenyl)borate; 4,4′-di-t-butylphenyliodoniumtetrakis(pentafluorophenyl)borate; tris(t-butylphenyl)sulphoniumtetrakis(pentafluorophenyl)borate,(4-methylphenyl-4-(1-methylethyl)phenyliodoniumtetrakis(pentafluorophenyl)borate, and the mixture thereof.

The mixed proportion of the photoacid generator in the present inventionis 0.1 to 100 parts by weight relative to 100 parts by weight of thecyclic olefin resin, and more preferably 0.1 to 10 parts by weight.

A sensitizer can be used for the cyclic olefin resin composition of thepresent invention for higher photosensitivity as necessary. Thesensitizer can extend a wavelength range capable of activating thephotoacid generator, and can be added in a range which has no directinfluence on the cross-linking reaction of the polymer. The optimalsensitizer has the maximum light absorption coefficient near the usedlight source and can pass the absorbed energy to the photoacid generatorefficiently. Examples of the sensitizers for the photoacid generatorinclude polycyclic aromatic compounds such as anthracene, pyrene andparylene. Examples thereof include 2-isopropyl-9H-thioxanthen-9-ene,4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthene,phenothiazine, and the mixture thereof. The mixed proportion of thephotoacid generator in the present invention is 0.1 to 10 parts byweight relative to 100 parts by weight of the polymer, and morepreferably 0.2 to 5 parts by weight. When the light source has a longwavelength such as a g line (436 nm) and an i line (365 nm), thesensitizer is effective for activating the photoacid generator.

The resolution can be enhanced by adding small quantity of acidscavenger as necessary into the cyclic olefin resin composition of thepresent invention. The acid scavenger absorbs acids diffused to a nonlight-exposed portion during the photochemical reaction. Examples of theacid scavengers include, but are not limited to, a second and thirdamines such as pyridine, lutidine, phenothiazine, tri-n-propyl amine andtriethyl amine. The mixed proportion of the acid scavenger is 0.10 to0.05 parts by weight relative to 100 parts by weight of the polymer.

In the present invention, additive agents, such as a leveling agent, anantioxidant, a fire retardant, a plasticizer, a silane coupling agentand a filler can be added as necessary into the resin compositioncontaining the cyclic olefin resin (A) having an epoxy group and thephotoacid generator (B).

In the present invention, these components are dissolved in a solventand used in a varnish state. Examples of the solvents includenon-reactive and reactive solvents. The non-reactive solvent acts as thecareer of the polymer or additive, and is removed in the processes ofthe coating and curing. The reactive solvent contains a reactive grouphaving a compatibility with the curing agent added into the resincomposition. Examples of non-reactive solvents include hydrocarbonsolvents and aromatic solvents. Examples of the hydrocarbon solventsinclude, but are not limited to, alkane and cycloalkane such as pentane,hexane, heptane, cyclohexane and decahydronaphthalene. Examples of thearomatic solvents include benzene, toluene, xylene and mesitylene.Diethyl ether, tetrahydrofuran, anisole, acetate, ester, lactone, ketoneand amide are also useful. As the reactive solvents, cyclo ethercompounds such as cyclohexene oxide and α-pinene oxide, aromaticcycloethers such as [methylenebis(4,1-phenyleneoxymethylene)]bisoxirane, alicyclic vinyl ether compounds such as1,4-cyclohexanedimethanoldivinyl ether, and aromatic compounds such asbis(4-vinylphenyl)methane may be used singly or in admixture. Thereactive solvent is preferably mesitylene and decahydronaphthalene. Theyare optimal for coating resins on substrates made of silicon, siliconoxide, silicon nitride and silicon oxynitride or the like.

The resin solid content of the resin composition used for the presentinvention is 5 to 60% by weight. The resin solid content is morepreferably 30 to 55% by weight, and still more preferably 35 to 45% byweight. The viscosity of the solution is 10 to 25,000 cP, and preferably100 to 3,000 cP.

The resin composition used for the present invention is prepared bysimply mixing the cyclic norbornene resin having an epoxy group, thephotoacid generator, and as necessary, the solvent, the sensitizer, theacid scavenger, the leveling agent, the antioxidant, the fire retardant,the plasticizer, the silane coupling agent and the filler or the like.

The cure temperature of the resin composition used for the presentinvention is preferably 250° C. or less, and more preferably 210° C. orless. Since the cure temperature exceeding 250° C. causes thesimultaneous oxidization of copper wiring in curing, there exists aproblem in that the resistance value is increased.

When the elastic modulus after curing of the resin composition used forthe present invention exceeds 2.0 GPa, the stress of the resin itselfcauses the occurrence of cracks in a chip or reduces the curing foreasing external stress. The elastic modulus of less than 0.1 GPa maycause the occurrence of cracks in metal when a metal layer is formed onan insulating layer. The elastic modulus is preferably 0.4 GPa to 1.0GPa.

When the dielectric constant after curing of the resin composition usedfor the present invention is 2.6 or more, a problem exists in thatsignal delay is caused. The dielectric constant is preferably 2.6 orless, and more preferably 2.50 or less.

A method for using the cyclic olefin resin composition used for thepresent invention will be explained. First, the resin composition iscoated on an appropriate substrate, for example, a silicon wafer, aceramic substrate and an aluminum substrate or the like. As the methodfor coating, there are spin coating using a spinner, spray coating usinga spray coater, immersion, printing, and roll coating or the like. Then,prebaking is conducted at 90 to 140° C. for about 1 to 30 minutes to drythe coating film, after which an actinic ray is applied in a desiredpattern. As the actinic ray, there can be used an X-ray, an electronbeam, an ultraviolet light and a visible light or the like. However, anactinic ray having a wavelength of 200 to 700 nm is preferable.

Baking is conducted after the irradiation of the actinic ray. This stepincreases the reaction velocity of epoxy cross-linkage. The bakingconditions are set to 50 to 200° C. for about 5 to 60 minutes. Thebaking conditions are preferably set to 100 to 150° C. for about 10 to40 minutes, and more preferably 110 to 130° C. for about 15 to 30minutes.

Then, the non-actinic ray-applied portion is dissolved and removed witha developing solution to obtain a relief pattern. Examples of thedeveloping solutions include hydrocarbon solvents such as alkane andcycloalkane e.g., pentane, hexane, heptane and cyclohexane, and aromaticsolvents such as toluene, mesitylene, xylene and mesitylene. There canbe used terpenes such as limonene, dipentene, pinene and menthane, andthere can be suitably used organic solvents prepared by adding anappropriate amount of a surfactant to the terpenes.

As the method for development, a means such as spraying, paddle,immersion and ultrasonic wave or the like is usable. Then, the reliefpattern formed by development is rinsed. As the rinsing liquid, alcoholis used. Then, a heat treatment is applied at 50 to 200° C. to removethe developing solution and the rinsing liquid, and the curing of theepoxy group is completed to obtain a final pattern having high heatresistance.

Next, the semiconductor device of the present invention will beexplained referring to the accompanying drawings. FIG. 1 is an enlargedsectional view of a pad portion of a semiconductor device having a bump,of the present invention. As shown in FIG. 1, an Al pad 2 for input andoutput is formed on a silicon wafer 1; thereon is formed a passivationfilm 3; and a via hole is formed in the passivation film 3. Thereon isformed a polynorbornene resin film (a buffer coat film) 4. Furthermore,a metal (e.g. Cr or Ti) film 5 is formed so as to contact with the Alpad 2. The metal film 5 is removed by etching, in the vicinity of asolder bump 10 to secure insulation between pads. A barrier metal 8 anda solder bump 10 are formed for the insulated pad. Since the norborneneresin is excellent in low stress properties and the warpage of the waferis small, the exposure and the conveyance of the wafer can be performedwith high accuracy. Since the stress from the sealing resin can be easedalso in mounting, the damage of a Low k layer can be prevented, andthereby the semiconductor device having high reliability can beprovided.

EXAMPLES

The present invention is specifically described below by way ofExamples.

Example 1 Synthesis of Polymer

This example illustrates a copolymer (A-1) of 5-decyl-2-norbornene(hereinafter, referred to as “decylnorbornene”)/5-[(2,3-epoxypropoxy)methyl]-2-norbornene (hereinafter,referred to as “glycidyl methyl ether norbornene”)=50/50.

All glasswares were dried at 60° C. under a 0.1 torr vacuum for 18hours. The glasswares were then transferred into a glovebox and attachedto the glovebox. After ethyl acetate (917 g), cyclohexane (917 g), decylnorbornene (137 g, 0.585 mol), and glycidyl methyl ether norbornene (105g, 0.585 mol) were added into a reaction flask, the reaction flask wasremoved from the glovebox, and dry nitrogen gas was introduced into thereaction flask. The reaction medium was degassed by passing a stream ofnitrogen gas through the solution for 30 minutes. Inside the glovebox,9.36 g (19.5 mmol) of a nickel catalyst, i.e.,bis(toluene)bis(perfluorophenyl) nickel, was dissolved in 15 ml oftoluene, taken up in a 25 mL syringe, removed from the glovebox andadded into the reaction flask. The reaction was completed by stirringthe solution at 20° C. for 5 hours. Next, a peracetic acid solution (975mmol) was added, and the solution was stirred for 18 hours. Stirring wasstopped and water and solvent layers were allowed to separate. The waterlayer was removed and 1 liter of distilled water was added. The solutionwas stirred for 20 minutes. The water layer was permitted to separateand was removed. The wash with 1 liter of distilled water was performeda total of 3 times. Polymer was then precipitated by addition intomethanol. After the solid polymer was recovered by filtration andsufficiently washed with water, the solid polymer was dried undervacuum. 222 g of dry polymer (94% conversion) was recovered afterdrying. Polymer molecular weight by GPC Mw=114,000 Mn=47,000,monodispersity (PDI)=2.42. Tg by DMA=180° C. Polymer composition byH-NMR 48 mole % decyl norbornene: 52 mole % epoxy norbornene.

Example 2 Synthesis of Polymer

This example illustrates a copolymer (A-2) of decyl norbornene/glycidylmethyl ether norbornene=70/30.

All glasswares were dried at 60° C. under a 0.1 torr vacuum for 18hours. The glasswares were then transferred into a glovebox and attachedto the glovebox. After ethyl acetate (917 g), cyclohexane (917 g), decylnorbornene (192 g, 0.82 mol), and glycidyl methyl ether norbornene (62g, 0.35 mol) were added to a reaction flask, the reaction flask wasremoved from the glovebox, and dry nitrogen gas was introduced into thereaction flask. The reaction medium was degassed by passing a stream ofnitrogen gas through the solution for 30 minutes. Inside the glovebox,9.36 g (19.5 mmol) of a nickel catalyst, i.e.,bis(toluene)bis(perfluorophenyl) nickel, was dissolved in 15 ml oftoluene, taken up in a 25 mL syringe, removed from the glovebox andadded into the reaction flask. The reaction was completed by stirringthe solution at 20° C. for 5 hours. Next, a peracetic acid solution (975mmol) was added, and the solution was stirred for 18 hours. Stirring wasstopped and water and solvent layers were allowed to separate. The waterlayer was removed and 1 liter of distilled water was added. The solutionwas stirred for 20 minutes. The water layer was permitted to separateand was removed. The wash with 1 liter of distilled water was performeda total of 3 times. Polymer was then precipitated by addition intomethanol. After the solid polymer was recovered by filtration andsufficiently washed with water, the solid polymer was dried undervacuum. 243 g of dry polymer (96% conversion) was recovered afterdrying. Polymer molecular weight by GPC Mw=115,366 Mn=47,000,monodispersity (PDI)=2.43. Polymer composition by H-NMR 70 mole % decylnorbornene: 30 mole % epoxy norbornene.

Example 3 Synthesis of Polymer

This example illustrates a copolymer (A-3) of decyl norbornene/glycidylmethyl ether norbornene=40/60.

All glasswares were dried at 60° C. under a 0.1 torr vacuum for 18hours. The glasswares were then transferred into a glovebox and attachedto the glovebox. After ethyl acetate (917 g), cyclohexane (917 g), decylnorbornene (29.43 g, 0.144 mol), and glycidyl methyl ether norbornene(16.6 g, 0.212 mol) were added to a reaction flask, the reaction flaskwas removed from the glovebox, and dry nitrogen gas was introduced intothe reaction flask. The reaction medium was degassed by passing a streamof nitrogen gas through the solution for 30 minutes. Inside theglovebox, 1.59 g (3.63 mmol) of a nickel catalyst, i.e.,bis(toluene)bis(perfluorophenyl) nickel, was dissolved in 7 ml oftoluene, taken up in a 10 mL syringe, removed from the glovebox andadded into the reaction flask. The reaction was completed by stirringthe solution at 20° C. for 1 hour. Next, 180 g of ion-exchange resinAmberlite IRC-718 was added, and the solution was stirred for 5 hours.After the solution was filtered, polymer was then precipitated byaddition into methanol. After the solid polymer was recovered byfiltration and sufficiently washed with water, the solid polymer wasdried under vacuum. 74 g of dry polymer (92.5% conversion) was recoveredafter drying. Polymer molecular weight by GPC Mw=164,941 Mn=59,454,monodispersity (PDI)=2.77.

Example 4 Production of Photosensitive Resin Composition

After 228 g of the resin synthesized in Example 1 was dissolved in 342 gof mesitylene, 4-methylphenyl-4-(1-methylethyl)phenyliodoniumtetrakis(pentafluorophenyl)borate (0.2757 g, 2.71×10⁻⁴ mol),1-chloro-4-propoxy-9H-thioxanthone (0.826 g, 2.71×10⁻⁴ mol),phenothiazine (0.054 g, 2.71×10⁻⁴ mol), and3,5-di-t-butyl-4-hydroxyhydrocinnamate (0.1378 g, 2.60×10⁻⁴ mol) wereadded thereto, and dissolved. The resulting solution was filteredthrough a 0.2 μm fluoro-resin filter to obtain a photosensitive resincomposition.

Example 5 Evaluation of Properties

The produced photosensitive resin composition was coated on a siliconwafer using a spin coater, followed by drying on a hot plate at 100° C.for 10 minutes to obtain a coating film having a thickness of about 10μm. To this coating film was applied a light at 300 mJ/cm² through areticle using an i-line stepper exposure, NSR-4425i (manufactured byNikon Corporation). The coating film was then heated in order to promotethe cross-linking reaction of a light-exposed portion at 115° C. for 15minutes by the hot plate.

Then, the resulting material was immersed in limonene for 60 seconds todissolve and remove a non-light-exposed portion, and rinsed withisopropyl alcohol for 20 seconds. As a result, the formation of apattern could be observed. The residual film ratio (film thickness afterdevelopment/film thickness before development) was very high at 99.6%.In the remaining pattern, detailed pattern peeling was not observed atall, and excellent adhesiveness during the development could beobserved. The pattern was then cured at 200° C. for 60 minutes, and thecross-linking reaction was completed.

After a photosensitive resin composition was independently coated on asilicon wafer (thickness: 625 μm) of 6 inches similarly and prebaked,the photosensitive resin composition was cured by heating at 200° C. for60 minutes. The measured warpage of the wafer was 28 μm. Also, the waterabsorption of this cured film was 0.2%.

The stress calculated from change of the curvature radius of the waferbefore and after forming the photosensitive resin film was 7 MPa. Thedielectric constant measured in accordance with JIS C 6481 was 2.5.

Next, the manufacturing method of the semiconductor device having thewafer level package structure of the present invention will beexplained. Then, as shown in FIG. 2C, a wiring metal film was formed byplating. Then, as shown in FIG. 2D, the photosensitive resin compositionwas coated and a pattern (an insulating film) 7 was formed viaphotolithography. Then, as shown in FIG. 3B, a barrier metal 8 and asolder 10 were deposited in this order, by plating. Then, as shown inFIG. 4A, a flux 11 was coated and the solder 10 was melted by heating.Then, the flux 11 was removed by washing, to form a solder bump 12 asshown in FIG. 4B, and dicing was conducted along a scribing line toobtain individual chips.

Example 6

Preparation was made in the same manner as in Example 4 and evaluationwas made in the same manner as in Example 5 except that the resinsynthesized in Example 1 was replaced by 228 g of the resin synthesizedin Example 2. The results are shown in Table 1.

Example 7

Preparation was made in the same manner as in Example 4 and evaluationwas made in the same manner as in Example 5 except that the resinsynthesized in Example 1 was replaced by 228 g of the resin synthesizedin Example 3. The results are shown in Table 1.

Example 8

Evaluation was made in the same manner as in Example 6 except that thefilm thickness after coating was set to 20 μm in Example 6. The resultsare shown in Table 1.

Example 9

Evaluation was made in the same manner as in Example 6 except that thecuring conditions were changed to 160° C. for 60 minutes in Example 6.The results are shown in Table 1.

Example 10

Evaluation was made in the same manner as in Example 6 except that thecuring conditions were changed to 260° C. for 60 minutes in Example 6.The results are shown in Table 1.

Comparative Example 1

A flip chip similar to that of Example 1 was produced by using anon-photosensitive polyimide resin, CRC-6061 (manufactured by SumitomoBakelite Co., Ltd.). Coating was made, by using a spin coater, on awafer wherein a via hole had been formed in a passivation film using aresist. Then, drying was conducted on a hot plate at 140° C. for 4minutes to form a coating film having a thickness of about 10 μm.Thereon was coated a positive resist, OFPR-800 (manufactured by TokyoOhka Kogyo Co., Ltd.) by using a spin coater, followed by drying on ahot plate at 100° C. for 2 minutes to obtain a coating film having athickness of about 2 μm. To this coating film was applied a light at 400mJ/cm² through a reticle by using a g-line stepper exposure, NSR-1505G3A(manufactured by Nikon Corporation).

Then, the resulting material was immersed in a 2.38% aqueoustetramethylammonium hydroxide solution for 60 seconds to dissolve andremove the light-exposed portion, and was rinsed with pure water for 30seconds.

Then, the resulting material was subjected to curing in a clean ovenunder nitrogen atmosphere at 150° C. for 30 minutes and at 350° C. for30 minutes. The water absorption of the cured film was 1.5%. Thus, thecured film has a high water absorption of 1.5% and is inferior inreliability.

After a photosensitive resin composition was independently coated on asilicon wafer (thickness: 625 μm) of 6 inches similarly and prebaked,the photosensitive resin composition was cured by heating at 350° C. for30 minutes. The measured warpage of the wafer was 35 μm. The dielectricconstant of this cured film was 3.5.

Comparative Example 2

Evaluation was made in the same manner as in Example 1 except that thecuring conditions were changed to 150° C. for 30 minutes and 280° C. for30 minutes under nitrogen atmosphere in Example 1. Since the ringclosure reaction was insufficient at 280° C., cracks appeared in thebuffer coat film after the formation of a bump.

The results of measurements in Examples and Comparative Examples areshown in Table 1.

TABLE 1 Film Curing Elastic Dielectric Thickness Condition ModulusConstant Stress Polynorbornene (μm) (° C./min) (Mpas) (%) (MPa) Ex. 5A-1 10 200/60 0.60 2.5 7 Ex. 6 A-2 10 200/60 0.45 2.5 5 Ex. 7 A-3 10200/60 0.80 2.6 9 Ex. 8 A-2 20 200/60 0.45 2.5 5 Ex. 9 A-2 10 160/600.45 2.5 5 Com. CRC-6061 10 350/30 3.00 3.5 35 Ex. 1 Com. CRC-6061 10280/30 2.80 3.8 30 Ex. 2

INDUSTRIAL APPLICABILITY

The present invention is used suitably for a resin-sealed semiconductordevice having a lead on chip structure which is excellent in low stressproperties, solvent resistance, low water absorbency, electricinsulation properties and adhesiveness or the like.

1-10. (canceled)
 11. A photosensitive resin composition containing acyclic olefin resin (A) having an epoxy group and a photoacid generator(B), which provides after curing a resin layer having an elastic modulusof 0.1 GPa or more but no more than 2.0 GPa, wherein the cyclic olefinresin (A) having an epoxy group contains a repeating unit represented bythe formula (1):

wherein X is O, CH₂ or (CH₂)₂; n is an integer of 0 to 5; R¹ to R⁴ areeach independently selected from hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an aryl group, an aralkyl group, afunctional group containing an ester group, a functional groupcontaining a ketone group, a functional group containing an ether group,and a functional group containing an epoxy group; R¹ to R⁴ may bedifferent in a repetition of a monomer; and at least one of R¹ to R⁴ inall the repeating units is the functional group having an epoxy group.12. A photosensitive resin composition according to claim 11, whereinthe cyclic olefin resin (A) having an epoxy group contains repeatingunits represented by the formulae (2) and (3):

wherein R¹ to R⁷ are each independently selected from a hydrogen atom,an alkyl group, an alkenyl group, an alkynyl group, an aryl group, anaralkyl group, a functional group containing an ester group, afunctional group containing a ketone group, and a functional groupcontaining an ether group; and R¹ to R⁷ may be different in a repetitionof a monomer.
 13. A photosensitive resin composition according to claim11, wherein the cyclic olefin resin (A) having an epoxy group containsrepeating units represented by the formulae (4), (5) and (6):

wherein n is an integer of 0 to 5; R¹ to R¹⁰ are each independentlyselected from hydrogen atom, an alkyl group, an alkenyl group, analkynyl group, an aryl group, an aralkyl group, a functional groupcontaining an ester group, a functional group containing a ketone group,and a functional group containing an ether group; and R¹ to R¹⁰ may bedifferent in a repetition of a monomer.